The MIMO (Multi-Input Multi-Output) technique which simultaneously utilizes a plurality of frequency bands has been put into use so as to provide a communication with a higher speed and a larger capacity in mobile communicating equipment which is represented by a smart phone or a tablet. Each frequency band needs a RF component. If the frequency bands for communication are increased in number, each component needs to be further downsized and provided with more functions to maintain the original size of the equipment where increased components are disposed.
Such an electronic component working at a high frequency can be, for example, a diplexer, a band-pass filter or the like. All of these components contain the combination of dielectric material(s) functioning as capacitor and magnetic material(s) functioning as inductor. In order to provide good high-frequency characteristics, each kinds of loss at a high-frequency region are required to be suppressed.
The requirements for the dielectric material are as follows. (1) According to the requirements for downsizing, the relative permittivity (∈r) is required to be high in order to decrease the area of the capacitor. (2) The dielectric loss is required to be low, i.e., the Q value is required to be high in order to obtain a good selectivity in frequencies. (3) The breakdown voltage is required to be high.
For example, as the representative material having a low dielectric loss in the GHz band, the amorphous film of SiNx can be mentioned. However, its relative permittivity (∈r) is as low as 6.5, so a large area is needed to provide the target functions. In this respect, it is hard to meet the downsizing requirements.
In Patent Document 1, a technique involving Ba(Mg1/3 Ta2/3)O3 which is a kind of material with a low dielectric loss (i.e., a high Q value) has been disclosed. This kind of material is a condensed sintered compact obtained by a thermal treatment at a temperature of 1500° C. or higher, and its relative permittivity (∈r) at 10 GHz is 24.7 and the Q value is 51000.
In addition, it has been disclosed in Non-Patent Document 1 that Ba(Mg1/3 Ta2/3)O3 is subjected to depositing film by the PLD method (i.e., pulsed laser deposition method) and then crystallized via a thermal treatment at 600° C. so as to provide a relative permittivity (er) of 33.3 at 2.66 GHz and a tan δ of 0.0158 (the value is 63.3 when calculated in terms of Q value).